Bay Area Scientists in Schools Presentation Plan
Lesson Name Chalk One Up for Science! pH and Chemical Reactions
Presenter(s) Lena Daumann, Billy Hart-Cooper
Grade Level 5 Standards Connection(s) 5-PS1 Matter and Its Interactions
Next Generation Science Standards
5-PS1-3. Make observations and measurements to identify materials based on their properties.
5-PS1-4. Conduct an investigation to determine whether the mixing of two or more substances results
in new substances.
Science and Engineering
Disciplinary Core Ideas
Crosscutting Concepts
Practices
Planning and Carrying Out
Structure and Properties of
Cause and Effect
Cause and effect relationships are
Investigations
Matter
Conduct an investigation
collaboratively to produce data to
serve as the basis for evidence,
using fair tests in which variables
are controlled and the number of
trials considered. (5-PS1-4)
Make observations and
measurements to produce data to
serve as the basis for evidence for
an explanation of a phenomenon.
(5-PS1-3)
Measurements of a variety of
properties can be used to identify
materials. (Boundary: At this grade
level, mass and weight are not
distinguished, and no attempt is
made to define the unseen
particles or explain the atomicscale mechanism of evaporation
and condensation.) (5-PS1-3)
routinely identified, tested, and
used to explain change. (5-PS1-4)
Scale, Proportions, and
Quantity
Standard units are used to measure
and describe physical quantities
such as weight, time, temperature,
and volume. (5-PS1-3)
Chemical Reactions
When two or more different
substances are mixed, a new
substance with different properties
may be formed. (5-PS1-4)
Common Core State Standards Connections
ELA/Literacy
W.5.7 Conduct short research projects that use several sources to build knowledge through
investigation of different aspects of a topic (5-PS1-3),(5-PS1-4)
W.5.8 Recall relevant information from experiences or gather relevant information from print and
digital sources; summarize or paraphrase information in notes and finished work, and provide a list of
sources. (5-PS1-3),(5-PS1-4)
W.5.9 Draw evidence from literary or informational texts to support analysis, reflection, and research.
(5-PS1-3),(5-PS1-4)
Mathematics
MP.2 Reason abstractly and quantitatively. (5-PS1-3)
MP.4 Model with mathematics. (5-PS1-3)
MP.5 Use appropriate tools strategically. (5-PS1-3)
Teaser: Visiting scientists will work with small student groups to test the pH of several household
items, followed by student Q&A. Carbon dioxide will then be discussed in the context of combustion
reactions and climate change (ocean acidification). The visiting scientists will complete an experiment
with their student group that involves making calcium carbonate (chalk) from CO 2 , calcium chloride
and water (followed by Q&A). The effect of CO 2 on water pH will be discussed. Finally, the visiting
scientists will demonstrate how water can be used to rapidly convert solid CO 2 to a gas, which can be
used to create soap bubbles.
Objective: In this lesson, students will learn about two important chemicals, water and carbon dioxide.
For water, the concepts of acidity and basicity will be introduced, emphasizing (1) common types of
acidic and basic solutions commonly encountered, (2) how to determine if something is acidic or basic
using cabbage juice and (3) important safety considerations of acids and bases.
Vocabulary/Definitions: 3 – 6 important (new) words
Acid, Base, pH, carbon dioxide, hypothesis, chemical reaction, indicator
Materials:
What will you bring with you?
cabbage indicator, different household items
with different pH (baking powder, baking soda,
sour patch kids, lemon juice, lemonade,
windex, vinegar, sparkling water). Setup for
Making Chalk, safety glasses
What should students have ready?
writing material
Classroom Set-up: The students should be divided into 4-5 groups and gather around one table each.
1.
Classroom Visit
Personal Introduction:
5 Minutes
Who are you? What do you want to share with students and why? How will you connect this with
students’ interests and experiences?
We are scientists from UC Berkeley. What do we do, what do we study (Molecules etc.). Chemistry is
important because chemical reactions happen all around us every day (body, gasoline, cooking).
Learning chemistry helps us to understand our world better and improve our world (understand what
chemicals are polluting our air, make new medicines).
Topic Introduction:
10 Minutes
What questions will you ask to learn from students? Big Idea(s), vocabulary, assessing prior
knowledge…
Chemical Reaction – process in which molecules rearrange into different products that have different
properties. Sometimes we can see chemical reactions occurring (bubbles, color change). In today’s
reaction we’ll see a color change. We will learn about 2 types of chemicals called acids and bases:
Many things around your house are acids and bases and we’ll explore this more today. An acidic
solution has excess H+ molecules, a basic solution has excess OH- molecules, neutral solution is
neither acidic or basic. Scientists use something called a pH scale to measure how acidic or basic a
solution is. The scale goes from 0 to 14 (draw on board, mark acids and bases on scale). Today’s
chemical reaction: A purplish colored molecule in cabbage juice reacts with acids and bases with a
color change. Therefore cabbage juice can be used to indicate if a solution is acidic or basic so it is
called an indicator. Demonstration: water with methylene blue indicator, add dry ice, makes it acidic,
color change, lead over to experiment with cabbage juice indicator
2.
Learning Experience(s):
30 Minutes
What will you do, what will kids do? Demonstrations, hands-on activities, images, games,
discussion, writing, measuring… Describe in order, including instructions to kids.
Experiment 1: As a group the budding scientists will order the food and household products along the
pH scale and fill out the hypothesis (prediction) for each product in each column of the worksheet.
Then the students will use the cabbage indicator solutions to test the acidity and basicity of the
products. Discuss in the group whether hypotheses were correct; fill out worksheet with pH of the
household items. The students will then take a piece of Antacid (Tums) and put it into one of the
acidic solutions discuss their observation with their peers.
Experiment 2: The visiting scientists will make chalk (calcium carbonate) by bubbling CO 2 through a
basic solution containing CaCl 2 . The students will describe their observations and apply the
knowledge about acids and bases. After a while the solution will become too acidic due to excess CO 2
and the chalk will dissolve again, the visiting scientist will talk about the problem of CO 2 in the
atmosphere and ocean acidification and what this means for see critters that have shells or corals.
3.
Wrap-up: Sharing Experiences
10 Minutes
Putting the pieces together – how will students share learning, interpret experience, build
vocabulary?
What did we learn today about acids and bases? Were our hypotheses always correct? How does CO 2
react in water? Finally, the visiting scientists will demonstrate how water can be used to rapidly
convert solid CO 2 to a gas, which can be used to create soap bubbles.
4.
Connections & Close:
5 Minutes
What else might kids relate this to from their real-life experience? How can they learn more?
Thanks and good-bye! Clean-up.
Total 60 Minutes
Acids and Bases - Cabbage Indicator
WORKSHEET
1) As a group, order the food and household products along the pH scale. Fill out your hypothesis
(prediction) for each product in each column.
Product
Hypothesis: acid, base or neutral?
pH
Windex
Baking Soda
Baking Powder
Sour Patch Candy
Lemon Juice
Sprite
Vinegar
Sparkling Water
2) Use the cabbage indicator solutions to test the acidity and basicity of the products. What do
you observe? You can use the pH indicator strips, too! Was your hypothesis in 1) correct?
3)
4) Complete the table based on your observations. Write down the pH of that product in the
correct column.
5) Take a piece of Antacid (Tums) and put it into one of the acidic solutions. What happens? Why?
Turn page over
WORKSHEET
Experiment 2: Making chalk (calcium carbonate)
The visiting scientist needs your help in setting up their chalk-making device!
1. What happens after you start bubbling CO 2 through a basic solution containing CaCl 2 ?
2. What happens after you continue bubbling CO 2 through the solution?
3. Add some baking soda to an acidic solution. What happens?